This invention relates to a process for producing ammonium nitrite. More particularly, it relates to an improved process for producing ammonium nitrite by contacting in an absorption system a gaseous stream containing nitric oxide, nitrogen dioxide and oxygen with an aqueous solution containing a basically reacting ammonium compound, said process characterized by improved yield and reduced nitrogen oxide emission accomplished by controlling the pressure, and preferably adding controlled supplemental quantities of nitrogen dioxide to the absorption system.
One of the principal uses of ammonium nitrite is for the production of hydroxylamine compounds. For such work, an aqueous solution of ammonium nitrite can be used.
The nitrite-producing reaction dealt with herein can be considered as a type of gas absorption, including physical absorption of gaseous components by the basic ammonium compound solution and stripping of volatile components from this solution, together with a multiplicity of liquid phase and gas phase reactions and side reactions. While the complexity and rapidity of what occurs during absorption may preclude exact knowledge of the chemical and physical mechanisms for the process, the following equations will serve as a guide for understanding the reaction using, for example, ammonium bicarbonate as the basic ammonium compound added to the absorbing solution.